Tech tips, mostly to do with Linux, Ubuntu, Grails, PHP, development tools and so on...

Sunday, 18 December 2011

belongsTo Relationships in Grails and DB schema

There are three (two actually as far as DB schemas are concerned) types of belongsTo relationships in Grails:

The first one "belongsTo = [customer: Customer" defines a one-to-one relationship between CustomerOrders and Customers. It stores the reference in the "CUSTOMER_ORDER" table in a "CUSTOMER_ID" column:

The second and third types of belongsTo relationships produce the same type of schema, with neither the "CUSTOMER" or "CUSTOMER_ORDER" tables containing references to each other, but rather that relationship information being kept in a "CUSTOMER_CUSTOMER_ORDER" table.